An information system for firefighters has become known from DE 101 03 922 A1. The prior-art information system comprises a mobile fire station command center and helmet systems, which are carried by the firefighters. This helmet system comprises an image recording means for an image that can be received over the eyes, a display means, which can be perceived in the range of vision, as well as infrared and laser sensors. Each helmet system is equipped for communication with a radio transmission system, which communicates bidirectionally with the mobile fire station command center. The signals received from the individual image recording means are displayed on monitors there. Additional information, e.g., orientation data obtained by means of the position sensors and points of the compass, may also be faded into the field of view of the firefighter via the display means. Due to the linking of the helmet systems via the mobile fire station command center, the position of a fire fighter colleague can be faded in via the display means by corresponding processing of the position information recorded.
The drawback of the prior-art information system is that position sensors can record the position only inaccurately and as a result, a firefighter cannot be immediately located in a hazardous situation, especially if smoke is also intensely released at the same time. Positioning systems, such as GPS, are, moreover, unsuitable for use within buildings.